1. Field of the Invention
The present invention relates to disk brakes, and in particular to a disk brake having a noise suppression feature to inhibit unusual or uncommon noise generation.
2. Description of the Related Art
A known disk brake has many problems to be solved. One of the problems is unusual noise generated by the braking system. Various measures suppressing unusual or uncommon noise have been applied to the disk brake.
In general, when a disk rotor or a pad is exposed to water, the frictional coefficient between the disk rotor and the pad increases or at least becomes unsteady. As a result, an uncommon noise is generated between the disk rotor and the pad. A known disk brake, as described in Japanese Laid-Open Patent Publication No. 2000-136839, has chamfering or a slit formed on the friction surface of an outer pad. The chamfering or the slit functions to remove the water from between the disk rotor and the pad. Thereby, the unusual noise generated due to the water exposure can be suppressed.
Moreover, in the disk brake the sliding surface of an inner pad may have a larger length in a sliding direction as compared with the outer pad. Thereby, vibration in the disk rotor generated by a high decelerating speed can be strongly suppressed by the inner pad. In addition, a mounting is typically fixed on a car body member in a cantilever manner. The inner pad is supported at the base end side of the mounting. The outer pad is supported at the tip end side of the mounting. Therefore, the inner pad is more stably supported than the outer pad so that the inner pad can reliably suppress the vibration of the disk rotor. As a result, generation of unusual noises can be effectively suppressed.
As shown above, the inner pad can effectively suppress unusual noises that may be generated due to water exposure and high decelerating speeds. However, the noise suppression ability of the outer pad has not been fully addressed by the known disk brakes.